Optimisation Of Lasing Metasurfaces With Symmetry Constraints On The Modes

Metasurfaces that are infiltrated with active materials, such as dyes or up-converting nano-particles, offer many advantages for novel lasing systems, such as high directionality and low lasing threshold. However, such metasurface lasers require the optimisation of two metasurface modes that are resonant at both the absorption and lasing wavelength bands. The absorption band also requires a weak angular dispersion to allow for a large acceptance angle for the absorption. Here we propose and numerically demonstrate a novel technique to quantity and optimise these bands. Our technique is based on symmetry analyses of the eigenmodes of the metasurface and allows us to optimise mode volume into the active media, as well as the directionality of the lasing emission.